"Semitrailer" means every vehicle without motive power designed to be drawn by a vehicle, motor vehicle, or truck tractor and so constructed that an appreciable part of its weight and that of its load rests upon and is carried by such other vehicle, motor vehicle, or truck tractor. (Added by Ord. 96-028 § 8, June 12, 1996, Eff date June 29, 1996).